There are disclosed in the prior art many acrylate esters of organic polyols which are useful as polymerizable monomers. Certain acrylate esters of organic polyols, such as neopentyl glycol diacrylate and the diacrylate compounds described in U.S. Pat. No. 3,645,984 (e.g., 3'-acryloxy-2',2'-dimethylpropyl 3-acryloxy-2,2-dimethylpropionate), are particularly useful in forming hard, mar-resistant coatings. However, problems have been encountered in preparing acrylate esters such as these in that the acrylyl moieties tend to undergo polymerization under the same conditions which promote the esterification reaction between the polyol and acrylic or methacrylic acid.
The prior art discloses preferred reaction temperatures for esterification reactions between acrylic or methacrylic acid and "higher" alcohols (i.e., more than 3 carbon atoms) of greater than 95.degree. C. (see, e.g., U.S. Pat. No. 3,645,984 and Canadian Pat. No. 768,651). The polymerization inhibitors which are effective at inhibiting polymerization of the acrylyl moiety at temperatures above 95.degree. C. (e.g., phenothiazine, methylene blue, and hydroquinone) impart color to the reaction product, which color is difficult to remove by means other than distilling the product. However, many of the acrylate esters of higher alcohols can only be conveniently recovered as residue products, thus, it is difficult to produce residue acrylate esters of organic polyols having low color (i.e., less than 4.0 Gardner) by processes of the prior art. This has largely excluded the use of residue acrylate esters which have otherwise excellent coating properties from uses where it is desired to produce a clear, colorless coating.